This invention relates to ground working devices.
A road resurfacing unit is disclosed in U.S. Pat. No. 5,795,096 issued Aug. 18, 1998, which uses teeth to rip a gravel road prior to separating coarse material from fine material and depositing the coarse material on the fine material. It is desirable to have efficient separation of coarse and fine material. The design in U.S. Pat. No. 5,795,096 uses discs commonly used in farm implements. While these work satisfactorily, there is room for improvement. The inventor has proposed a solution to the need for improved separation.
Therefore, in one aspect of the invention, there is provided a ground working device, comprising a sub-frame having a first side and a second side, plural discs mounted for rotation on the sub-frame between the first side and the second side about an axis that extends from the first side to the second side; and a set of scoops mounted on each disc in ground contacting position. The scoops efficiently lift the ground surface material, which falls to the ground in a sorted manner with coarser material on top. In a further aspect of the invention, a motor is operatively connected to the plural discs for rotating the discs about the axis. Preferably, each scoop in each set of scoops has a ground working face that extends transversely to the disc on which the respective scoop is mounted. Also, preferably, the scoops each have concave ground contacting surfaces. Each scoop is preferably received in a respective slot in the disc in which the respective scoop is mounted. In a further aspect of the invention, there is provided a main frame on which the ground working device is mounted, the main frame being provided with ground engaging wheels. The sub-frame is preferably retractably mounted on the main frame. In use, the ground working device is preceded by a ripper bar mounted on the frame, which rips the ground surface. The ripper bar may be formed with retractable, replaceable teeth.
These and other aspects of the invention are described in the detailed description of the invention and claimed in the claims that follow.